DeviceAccessFacadeImpl.java 文件源码

private Completable inflatePublishers(Iterable<DeviceAccess> deviceAccesss, DeviceAccessQuery query) {
    // Return as complete if publisher is not a requested field
    if (query.getInflationPolicy() == null || !query.getInflationPolicy().hasChildField(DeviceAccessQuery.PUBLISHER_FIELD)) {
        return Completable.complete();
    }

    Multimap<Long, DeviceAccess> deviceAccesssByPublisherId = HashMultimap.create();

    return Observable.fromIterable(deviceAccesss)
            // Filter out publisher sessions with no publisher
            .filter((deviceAccess) -> deviceAccess.getPublisher() != null && deviceAccess.getPublisher().getId() != null)

            // Collect all of the publisher sessions and their publisher IDs into a map
            .collectInto(deviceAccesssByPublisherId, (map, deviceAccess) -> map.put(deviceAccess.getPublisher().getId(), deviceAccess))

            // Fetch all of the publishers for those publisher IDs
            .flatMapObservable((map) -> map.keySet().isEmpty()? Observable.empty() : publisherFacade.filter(new PublisherQuery().ids(map.keySet())))

            // For each publisher returned, map it to each publisher session that had its ID
            .flatMapCompletable((publisher) ->
                    Observable.fromIterable(deviceAccesssByPublisherId.get(publisher.getId()))
                            .flatMapCompletable((deviceAccess) ->
                                    Completable.fromAction(() -> deviceAccess.setPublisher(publisher))
                            )
            );
}